Summary:
The implementation delegates to the Platform to perform the actual
show/hide of the cursor image.
This replaces the implementation in the zoom effect which so far
directly interacted with xfixes to show/hide the cursor. This is now
provided by the x11/standalone platform. And due to this change the zoom
effect can now properly hide the cursor on platform DRM (wayland) as
well.
Test Plan: Zoom effect on Wayland hides the cursor
Reviewers: #kwin, #plasma_on_wayland
Subscribers: plasma-devel, kwin
Tags: #plasma_on_wayland, #kwin
Differential Revision: https://phabricator.kde.org/D3120